CS114391A2 - Suspension of polymer admixtures in functional liquids and in mixtures with thermoplastic resins - Google Patents

Description

Suspensions of polymeric additives in functional fluids and mixtures with thermoplastic resins

Technical field

The present invention relates to suspensions of polymeric additives in functional liquids. Suspensions of this invention exhibit enhanced stability and have a viscosity such that they can be readily and accurately metered into thermoplastic resins by conventional pumping means. In the case of suspensions which contain stabilizers, the resulting thermoplastic resin compositions are characterized by increased resistance to thermal, oxidative and / or photodegradation.

Background Art

When producing products using thermoplastic resins such as polyolefins, various additives are usually added to affect color, physical properties, ease of processability, and to inhibit oxidation and other types of degradation by stabilizing the physical properties of the resin and so on. the life expectancy of the resin product is extended. For example, polyolefins tend to be susceptible to degradation by various mechanisms, including those loaded with catalyst residues, those caused by exposure to high temperatures, those associated with high mechanical stress loads, and those caused by exposure to oxygen. , of different wavelengths of electromagnetic radiation. -? -

Such polymers are usually protected from degradation. by adding various stabilizers that have been found to delay the degradation process. Primary anti-oxidants such as octadecyl-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate and secondary antioxidants such as IRGAFOS 168 are powders at room temperature. The effectiveness of any additive in a thermoplastic resin, such as an antioxidant or other stabilizer, is dependent upon the particular additive employed and the amount used. Equally important is the uniformity that the additive is dispersed in the thermoplastic resin system. In particular, any additive and, in particular, stabilizers, will ultimately vary in its uniformity with its polymer dispersion.

The nature of the additive dispersion may also have other effects on the properties of the thermoplastic resin. For example, a poorly dispersed additive may contribute to poor mechanical properties, such as reduced tensile and tear strength, reduced resistance to low temperature bending, and less elongation. Poor dispersions may also affect the electrical properties of the resin in those applications where these properties are important, for example, by reducing the breakdown voltage of the polyolefin dielectric, and may contribute to electrical losses by increasing the effect and dielectric constant.

To date, various processes have been used to incorporate stabilizers and other additives into polymer systems. In one process, the additive is added during the production of the crude polymer. While this process may provide a reasonably good dispersion of the additive in the polymer, the inconvenience caused by the reaction conditions calculated during the polymer formation drastically limits both the amount and especially the types of additives that can be used, especially in the case of a stabilizer. In another method, the resins in the molten form and additives are mixed in a high shear mixer.

In order to obtain an acceptable dispersion, this systemrelatively high shear force requires considerable temperatures at elevated temperatures sufficient to form a polymer melt. Since many additives in conventional use have high melting temperatures, they do not melt during processing and often form agglomerates with themselves or with other components of the composition. Such agglomerates are difficult to break during processing, even at high shear rates, and thus contribute to the unevenness of the additive dispersion in the polymer product. Strenuous shear and temperature conditions can lead to degradation of the polymer itself, such as a reduction in molecular weight. Such changes generally lead to deterioration of the polymer properties.

In addition, the addition of additive powders to the polymer melt by high shear mixing proves to be very difficult for continuous processing since it is often difficult to dispense such powdered materials at a uniform rate. U.S. Patent No. 3,000,854 discloses a method for controlling the rate of antioxidant delivery to a continuously extruded polymer using an ultraviolet analyzer for feedback control. - 4 -

Unfortunately, this process is limited to antioxidants that can be detected by ultraviolet absorbents such as alkyl substituted phenols. For analysis, the polymer must be melted and maintained as a melt in the analyzer. In addition, this technology suffers from the same drawbacks noted above with respect to high shear mixing to disperse such components in the polymer system.

Another technology that is known and which prevents high shear mixing is described in U.S. Pat. According to the process, polyethylene in particulate form, for example in the form of pellets, is introduced at room temperature into a tape mixer with an agitating or inverting action and antioxidants in small amounts, such as 0.01 µl ft 10 parts per 100 parts polyethylene pellets, are introduced at the start of the mixing cycle and are randomly dispersed into the pellet mass. The molten dicumyl peroxide composition is then added such that the surface of the polyethylene is dusted with the oxidant adhering thereto and coated with peroxide.

Unfortunately, the obtained dispersion is often arbitrary and generally uneven with some pellets that do not have an antioxidant coating at all. Antioxidants may preferentially adhere to some pellets due to static charge, which may be formed unevenly on surfaces by pellet fluctuations during mixing. Subsequent addition of peroxygen peroxide to coat the particles uniformly and this may result in the introduction of antioxidant particles into the pellets. However, due to the initial poor dispersion of the antioxidant, the resulting pellets retain an uneven dispersion of the antioxidant. - 5 ~

Another disadvantage is that this process leads to the formation of excessive amounts of dust due to the abrasion of the polyethylene pellets.

It is also known to mix additives such as antioxidants or stabilizers into the thermoplastic resin when extruding the melt. This method tends to work at a lower shear rate but inadequately distributes the finely divided additives, such as stabilizers, evenly throughout the resin. Dad's method can only be effective for mixing, namely homogeneous mixing, large quantities of material.

U.S. Patent No. 4,101,512 to Schmidt discloses the introduction of an antioxidant into a crosslinked polyethylene resin using a crosslinking agent as a proantioxidant solvent. The antioxidant solution in the crosslinking agent mixes with the granules or pellets crosslinkable by the polyethylene using a tape mixer. Since peroxide is added in the liquid form as a melt, this significantly ensures lubrication function and thus avoids the formation of fine particles, which are disclosed in U.S. Pat. No. 3,455,752, wherein the liquid sizing agent helps to disperse the antioxidant evenly in the polyethylene pellets. .

British Patent No. 1,133,505 discloses a method of incorporating antioxidants into solid porous polyolefin particles, wherein the antioxidant is dissolved in a solvent capable of evaporating at a temperature below the softening point of the polyolefin and at a temperature at which the antioxidant is negligibly volatile. However, the polyolefin must be substantially non-solvent soluble. The solid porous particles of the polyolefin are immersed in the antioxidant solution for a time sufficient to permit or induce absorption of the antioxidant polyolefin solution. Then the solvent is removed by evaporation leaving an absorbed antioxidant in the polyolefin porous particles.

Due to the need to evaporate the significant amounts of solvent, this procedure requires large amounts of energy. In addition, this process presents pollution control problems, which requires significant energy expenditure to provide condensation and solvent removal from the waste gas from the treatment process. This process also causes severe pressures in the process of preparing the resin pellets. If there is no uniform degree of porosity initially in the pellets, there is a high probability that the distribution of the absorbed anti-oxidant or evenly. In yet another known process described by Ruter in U.S. Pat. No. 4,466,270, the polymer additive is dissolved or dispersed in a polymerizable cyclic ester. The ester-additive mixture is then added to the thermoplastic resin during melt extrusion either before or after the polymerisaciester. Pre-polymerization of the ester is proposed in those cases where the additive M does not form a solution or a stable dispersant of the cyclic ester. Otherwise, the ester polymerization is carried out in situ during the melt extrusion process. The success of this process depends largely on the compatibility of the polymerized cyclic ester and the particular polymer. '? ·

In addition, processing conditions are limited by the need to obtain sufficient polymerization of the ester, a requirement that may include the addition of other components such as the ester polymerization catalyst to the thermoplastic resin. Mixing and formulation formulations generally add to the addition of other ingredients which may inadvertently contribute to premature degradation of the resin and thus may not be able to adopt this process. % v

Hyche in U.S. Patent No. 4,898,616 discloses used emulsions for the addition of additives such as antioxidants to polymer particles. The emulsion is formed by mixing xx aqueous mixture of additives, emulsifiable wax, and base and surfactant at a temperature at which all solids are melted. The polymer particles are then contacted with the emulsion and, after drying, the polymer particles coated with the solids are obtained. In addition to requiring extensive energy expenditure to dry the aqueous wax emulsion, the process is dependent on ingredients that are not considered as polymeric additives such as wax itself and, in part, a combination of base and surfactant; forming a stable wax emulsion

Leung et al. U.S. Patent No. 4,857,593 discloses a method for increasing the production of thermoplastic polymers, wherein process additives, which may be a silicone oil, a substituent containing at least one alkylene oxide unit and an alkoxy, hydroxy, carboxy, epoxy, or amine group, and process adjuvant, added to the thermoplastic polymer. No appeal is given to the way in which materials are combined. In the examples, all additives were combined with the resin before mixing in a high-speed Henschel mixer.

In general, the present invention is directed to an improved method of incorporating various additives, including stabilizers, such as antioxidants, into thermoplastic polymeric materials, particularly polyolefin resins, which exhibit instability or degradation upon exposure to light, atmospheric conditions, and elevated temperatures. The invention avoids the drawbacks of the prior art and is simple to implement.

SUMMARY OF THE INVENTION

According to the present invention, a stable suspension of the additive in the liquid is used to facilitate dispersion of the additive, such as the antioxidant material, evenly in the thermoplastic resin. The stable liquid suspensions may be dispersed evenly in different thermoplastic resins by mixing the liquid suspension with the solid polymer particles or mixing the liquid suspension with the resins, for example during melt extrusion. Such processes result in an even dispersion of the additive with the resin.

Tests have shown that when using a stable suspending antioxidant in a carrier liquid to stabilize the polysolefin resin to thermal degradation, mixing the particulate polyolefin resin with a stable suspension, the resistance of the polymers to physical damage, and the color changes are significantly increased in multiple printing in relation to in cases where the solid antioxidant alone was mixed with the resin particles.

As stated, the present invention provides a uniform dispersion in a thermoplastic resin for all conventional solid additives for thermoplastic synthetic resins, including UV stabilizers, thermostabilisers, primary and secondary antioxidants, accelerators, rats, nucleating agents, catalyzed inactivators. acid neutralizers and other similar stabilizers.

As used herein, the term "stabilizer" is intended to include all materials that can be added to the polymer blends for the purpose of improving the retention of the properties of the polymer under various exposure and use conditions. The better the dispersion of the stabilizing additive in the polymer, the better the efficiency of the stabilizer. All stabilizers contain polar groups and are often the cause of difficulty in dispersing into relatively non-polar polymer resins, especially polyolefin resins.

For example, the use of ETHANOX.RTM. 330 in polypropylene and polyamide, in this case, offers a relatively high molecular weight high-melting antioxidant (244 DEG C. / theoretically high quality) but has been excluded from many applications due to difficulties in obtaining uniform dispersions of this additive. v pi ^ yskyřici. For similar reasons, the relatively polar zinc oxide, a cheap acid scavenger, is also not commonly used to stabilize polyolefins since it is difficult to uniformly disperse. The present invention provides solutions to these problems by dispersing polar additives in non-polar polymers.

Specific examples of stabilizers include fatty amine and aainine and fatty amide antistatic agents and catalyst deactivators such as those sold by Wittco Chemical Comp. under the designations ΚΕΪ.1ΑΜΙΝΕ and KEMAM1DER and ATMERR 163; stabilizers comprising organic phosphites and other organic phosphorus compounds, such as tri-dodecyl phosphite, bis-substituted pentaerythritol phosphites, such as bis (2,4-di-butylphenyl) pentaerythritol diphosphite, available under the designation WBSTON, for example. .ris-

(mono- and dinonylphenyl) phosphite and products of CIBA-GEIGY IRGAF0SR including IRGAF0SR 168, phosphonites including fluorophosphonites such as ETHANOX R 398 and SANDOSTAB R P-EPQ companies.

Ethyl; hindered phenols such as octadecyl-3- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate, 10N0L / butylated hydroxy-toluene /, TOFANOLRCA / ICI /, IRGANOXR antioxidants marketed by Ciba -Geigy such as IRGAN0XR 1076, 1093, 1098 and IRGANXXR 1010 (Tetrakis [Methylene] -3- (3', 5'-di-tert-butyl-4'-h, hydroxyphenyl) propionate methanes, 3125 and 1425 and ETHANOXR antioxidants marketed by Ethyl Corp. such as BTHAN0XR 330 / 1,3,3-trimethyl-2,2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and ethaneaex ETHAN0XR 702a ISONOXR 129 Schenectady Chemical (2,2-ethylidene-bis (4,6-di-t-butyl) phenol); CIANOX®-antioxidants marketed by American Cyanamid including CYANOX® 1790 and 244-6 1 1 GOOD-RITE® antioxidants marketed by B.Foodworth Comp. including GOOD-RITER 3114 and 3125.

Furthermore, they are antioxidants / metal deactivators such as NAUGARD, a product marketed by Uniroyal Inc. NAUGARDR XL1 and IRGANOX1 * 1024 marketed by Ciba Geigy, thiodipropanate stabilizers such as dilaurylthiodipropionate and distearylthiodipropionate; hindered amine compounds such as tetraalkylpiperidinyl-containing compounds

R functional groups and benzotriazoles including TINUVIN, light stabilizers and UV absorbers marketed by Ciba-Geigy such as TINUVINR 144? TINUV1NR 326 and 327, TINU-VINR P, TINUVINR 622 LD, CHIMASSORB 944, CIANOX1 ^ 3346 American Cyanamid, GOQD-RITE 3034 and FAIRMOUNT MIXXIM 57,62, 63, 67 and 68; benzophenone stabilizers such as CYAS0RBR UV 2018 (American Cyanamid), UVINULRm40 and UVINULR490 (Antara Chemicals). Furthermore, mixtures of organic phosphorus compounds and phenylene phenolic antioxidants marketed by Ciba-Geigy under the designation IRGAN0XR including IRGAN0XR 1411,1412, 501W, 712FF, B-225, B-220, B-215, 561, 900 and 921; agents such as benzylidene disorbitol and benzoate; acid neutralizers including metal oxides such as zinc oxide; hydrotalcites; metal stearates; calcium calcium tat, magnesium aluminum hydroxycarbonates; stabilizers such as Mitsui DHT, Reheis L-55R, MILLADR 3905 A 3940 and the like.

Other suitable stabilizers include: bis (2,4,6-trimethylphenyl) entaerythritol diphosphite, bis (stearyl) pentaerythritol diphosphite, tris (2,4-di-butylphenyl) phosphite and 2,2'-ethylidene bis ( 4,6-di-tert-butylphenyl fluorophosphite 12 (ETHANOX® 398).

Further chemical identification of suitable stabilizers is as follows: CYANOX 1790 1,3,5-triis (4'-t-butyl-5'-hydroxy-2 ', 6'-dimethylbenzyl) isocyanurate CYANOX 2246 2,2'-methylenebis (4-methyl 6-t-butylphenol) -2,4,6-trimethylbenzene ISONOX 129 2,2'-ethylidenebis (4'6-di-t-butylphenol) GOOD-RITE 3114 1 13,5- "tris (3i, 5'-di-tert-4'-hydroxybenzyl) isocyanurate GGOD-RITE 3125 and IRGANOX 31 25 tris (3- (3 *, 5'-di-tert-butyl-4'-hydroxybenzyl) -2 '' -acetoxystearyl ') isocyanurate IRGANOX 1076 octadecyl-3- (3', 5'-di-t-butyl-4-hydroxyphenyl) propionate IRGANOX 1425 calciumbis (ethyl- (3,5- * dibutyl) IRGANOX 1024 N, N 'bis (beta-3,5, "di-butyl-4-hydroxyphenylpropion) hydrazide IRGANOX 1093 distearyl-3,5-di-tert-butyl- 4-Hydroxy-benzylphosphonate - 13 - IRGANOX 1098 IRGAFOS 168

SANDOSTAB-P-EPQ Ν, Ν'-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydroxycynnamamidetrium (2,4-di-butylphenyl) phosphite tetra (2 ', 4') n-di-tert-butylphenyl-4,4'-diphosphonite. Examples of materials suitable for use as liquid phase suspensions of the present invention are normally liquid silicates; normally liquid thermoplastic resin stabilizers; normally liquid hydroxylated polyoxyalkylenes and alkoxy terminally blocked products of these polyoxyalkylenes, and normally liquid polyalphaolefins and their hydrogenated products.

As used herein, the suspension is a generic termine including suspensions and dispersions.

Silicones that are used as continuous phase stable suspensions of this invention are synthetic polymers which may be represented by the general formula (R 3 S 10 1/2) 2 (R 2 S) x wherein R may be the same or different and may be any of the various monovalent organic moieties. a number equal to or greater than 1. - 14 -

Silicones known as polyorganosiloxanes have excellent thermal oxidation and hydrolytic properties, low surface tension, and are free of odor and prevent agglomeration of additives. These properties make them particularly suitable for use as carrier capsules. for mixing additives with thermoplastic resins. In particular, the present invention relates to the use of subclass synthetic silicone polymers which are liquid conditions used for mixing solid additives with thermoplastic resins, and in particular for extrusion of thermoplastic resins. Typically, such silicones have a molecular weight of from about 200 to about 150,000. Suitable silicone fluids may be linear, branched, or cyclic.

Silicone fluids that have been chemically modified to introduce suspension stability have a polar group such as hydroxy, hydroxyalkyl, carboxyl, amino, amide, carbamate, aldehyde, nitrile, phenol, vicinal epoxy, alkoxy, phosphite, phosphine, phosphonate a carboxylic acid ester, a polyether ether, for example a polyalkylene oxide, a thiol, a sulfite and / or other polar groups on a polysiloxane are particularly useful in the present invention.

Such silicone fluids generally have a double roll formation of a stable suspension with a solid additive or additive, which increases the dispersion of additives in the thermoplastic resin and serves as a thermoplastic adjuvant simultaneously. - 15 -

According to the broadest aspects of the present invention, a polar moiety that increases suspension stability can be deposited along the polymeric silicone backbone or as part thereof. a substituent attached to the silicone backbone. U.S. Pat. No. 4,778,838, which is incorporated herein by reference, discloses a known silicone polymer having tuco groups in both positions. Preferably, these groups are placed in a hinged position.

A preferred class of silicone fluids having only fed groups can be represented by the general formula I10 R1-Si-O

Si-0

SiO

Si-0

Si-R 12/1 / R 'R' 'wherein R' to R 'and R' may be the same or different and include alkyl groups, preferably those having 1 to 18 carbon atoms, aryl groups such as phenyl and alkylphenyls and other monoaluminum organic groups containing groups - 16 - selected from hydroxy, hydroxyalkyl, carboxyl, amino, amide, carbamate, aldehyde, nitrile, phenol, vicinal epoxy, alkoxy, phosphite, phosphine, phosphonate, carboxylic acid ester, polyether, for example polyalkylene oxide, thiol and sulfide wherein x, y and z may be the same or different and the sum of x, y and z is between 1 and 3,000.

As is known, the substituents on one silicon atom need not be identical. Thus, all methyl groups may be, or may be, a combination of two or more alkyl groups or other groups as defined above.

It will be appreciated that linear silicones may contain small amounts of branched silicones having small amounts of trifunctional or tetrafunctional siloxane units.

The simplest silicone fluids, chemically speaking, of the preferred formula I for use in the present invention are polydimethylsiloxanes. In the polydimethylsiloxanes, the substituents R to R in formula I are all methyl groups. Such compounds are generally represented by the formula wherein M represents the terminal trimethylsiloxy groups and D represents the repeating dimethylsiloxane units and n = x + y + z.

Such silicone capylins can be prepared by polymerizing the cyclic sulfoxane or mixtures thereof such as hexamethyltrisiloxane, octamethylcyclotetrasiloxane, or decamethylcyclopentasiloxane in the presence of an acid catalyst and a terminal such as hexamethyldisiloxane. - 17 -

As is well known to those skilled in the silicone chemical industry, a practical nomenclature has been developed which utilizes M, D, T and Q to represent monofunctional, difunctional, trifunctional and quadrifunctional siloxane monomer units. Commands or asterisks, such as D * or DK, are given to the letter symbols to designate non-methyl substituents. For example, silicone (CH 3 3 SiO- [(CH 2 2 -Sio] 10- [ch 3 (C 3 H 6 OH) sulfur] 3Q-Si (ClQ 3 is presented herein or in this nomenclature. Preferred silicone fluids may be represented by Formula I above wherein at least one substituent R @ 1 to R @ 5 is a monovalent organic group containing one of the aforementioned polar groups.

the most typical of all of them are the methyl groups and the '7' substituents, and the R 'and R' substituents contain one or more of the polar groups mentioned above and which increase the stability of the suspension.

In a preferred embodiment, x has a value between 0 and 2000, preferably between 5 and 750; y has a value between 1 and 500, preferably between 5 and 250, and z has a value between 0 and 500. Such polydiorganosiloxanes and in particular polydialkylsiloxanes are well known and need not be described in detail.

For example, dimethyl silicones suitable for use as carrier liquids may be provided with sterically hindered - 18 - amine groups for the light stabilization of thermoplastic resins, as described in U.S. Pat. No. 4,895,885 to which reference is hereby made; sterically hindered phenolic groups to stabilize the resin upon storage as described in U.S. Patent 4,879,378, to which reference is hereby made; phosphite groups to decompose peroxide; such polar groups as hydroxyalkyl to induce deactivation of residual catalysts; hindered amine light stabilizers; polyethylene oxide vicinal epoxy or amino groups to improve the processing of the thermoplastic resin (so-called "epoxy"); processing aids as described in Foster U.S. Pat. No. 4,533.U. Further, more than one functional group may be attached to the same polysiloxane backbone or mixtures of such functionalized polysiloxanes may be utilized to provide multiple effects in the resin .

Polysiloxanes,. which have different substituents in the attached positions along the backbone are well known. Such substances can be prepared by the catalytic addition of aliphatically unsaturated compounds having the desired substituent on the hydrosiloxanes in a molar ratio sufficient to consume hydrosiloxane groups or dehydrocondensation of alcohols by hydrosiloxanes. Usually a platinum catalyst such as chloroplatinic acid is used.

As is known to those skilled in the art, hydrosiloxanes can be prepared by reacting a mixture comprising octamethylcyclotetrasiloxane, 1,2,3,4-tetramethylcyclotetrasiloxane, a 19-chain terminator such as hexamethyldisiloxane and a acid catalyst. Instead of tetramethylcyclotetrasiloxane, trimethyl terminally blocked methyl hydrogen polysiloxane can be used.

By varying the molar ratio of the different reactants, the molecular weight and the number of different repeat units can be varied. Silicone fluid having a molecular weight of at least 1000 is preferred. The silicone liquid should be selected so as to have a solubility parameter that preferably fits solubility characteristics; see Charles M. Hansen, Journal of Paint Technography, 39/505; 104-117 (1967), to which reference is hereby made.

This requirement can be achieved by the appropriate chemical modification of the silicone fluid to introduce the polar stability enhancing moieties of the suspension having different polarity grades such as hydroxy, hydroxyalkyl, carboxy, amine, amide, carbamate, aldehyde, nitrile, phenol, vicinalepoxy, alkoxy, phosphite, phosphine, phosphonate, carboxylic acid ester, polyether, for example polyalkylene oxide, thiol and sulfide. Surprisingly, such a chemical modification of the siloxane polymer backbone will affect the interaction between the interililicon fluid and the additive that in most cases it is possible to prepare stable additive suspensions as a dispersed phase in the silicone fluid as a continuous phase.

Liquid-phase suspensions such as stabilizers suitable for use in the present invention are liquid tris (mono- and cinonylphenyl) phenylethyl phosphites marketed under the trademark WESTON by General Electrica Company such as tris (nonylphenyl) phosphite; phosphites such as tris (phenylethyl) phosphite and the like.

Among the suitable hydroxylated polyoxyalkylenesivable as continuous phases of the suspensions of this invention, hydroxyl-terminated polyoxy-alkylenes, such as poly (oxyethylene) glycols also referred to as polyethylene glycols marketed under the trademark CARBOWAX by Union Carbide Chemicals and Plastic Company Inc, may be noted. having the general formula (-O-20-20-h, and their alkoxy terminally blocked products, wherein each alkyl group has 1 to 6 carbon atoms including aa represents the number of oxyethylene groups; polyol-sold under the trademark PLURONIC by BASFWandandte, which are block polymers having ethylene oxide and propylene oxide units and alkoxy terminally blocked products of these copolymers, wherein each alkyl group has from 1 to 6 carbon atoms inclusive, monohydroxylated polyoxyalkylenes, which may be random or block polymers referred to herein.

Coatings Company does. having the general formula EMI5.1 by Union Carbide Chemicals and under the trademark UCON, k - 21 - r40 CH2CH-0

CH2-CH2OH; wherein is hydrogen or alkyl of 1 to 6 carbon atoms inclusive and their alkoxy (1 to 6 carbon atoms) end-blocked products; wherein b is at least 1 and c may be 0 or at least 1; poly (oxyalkylene) polyols such as glycerol-initiated (oxypropylene) triols and poles (oxypropyl) glycols, both sold by Union Carbide Chemicals and PlasticaCompany Inc, under the trademark NIAX.

Alkyl-terminally blocked products can preferably be produced, as is known, by reaction with an alkyl halide.

Liquid poly (alpha-olefins) are generally produced by the polymerization of one or more alpha-olefins, such as propylene, butene, 4-methylpentene, hexene, octene, decene, and the like.

Suitable poly (alpha-olefins) are marketed under the trademark HITEC by Ethyl Corporation. The present invention can be used to disperse additives in all conventional thermoplastic synthetic resins such as polyolefins, polystyrene, polyvinyl chloride, polyamides, polyesters, polycarbonates. , polyacrylates and polyethers, to name a few.

Polyolefins which may be particularly useful in the present invention include polyolefin homopolymers as well as interpolymers of one or more polyolefins by themselves and / or up to 30% by weight of one or more monomers copolymerizable with these olefins. Homopolymers and interpolymers including high-pressure, low-density polymers of these olefins such as ethylene, propylene, butene, isobutylene, hexene, 4-methylpentene, pentene, octene, nonene, decene and the like, as well as interpolymers of one or more such olefins of one or more other monomers that are inter-polymerizable with such olefins, such as vinyl and diene compounds, which are illustrated by ethylene copolymers containing ethylidene norbornene.

Also included in the term "olefin polymers" are mixtures of one polymer with at least one other polymer. Illustrations of these blends are ethylene / olefinic polymerics with at least one of the following components: polypropylene, high pressure low density polyethylene, high density polyethylene, polybutene-1, copolymers such as ethylene / acid acrylic copolymers, ethylene / methylacrylate copolymers, ethylene / ethyl acrylate copolymers, ethylene / vinyl acetate copolymers, ethoxylated copolymers and ethylene / vinyl acetate copolymers ethylene / acrylic acid / vinyl acetate terpolymers, also propylene copolymers with ethyl propylene elastomers and the like - 23 -

As used in this specification, which includes, "stable suspensions" are those where less than about 5% by weight separation of the liquid phase is detectable by formation of a two-phase system after centrifugation with a suspension of 100 x greater than the gravity of gravity (100 g / po) for 1 hour. Particularly desirable are those suspensions which exhibit less than 5% weight separation after centrifugation at 1400 g for 4 hours.

Suspensions having less than about 5% volume by volume after centrifugation at 1400 g for 4 hours are considered stable under normal conditions for at least 4 months. The gravimetric stability of the suspensions of this invention is manifested, for example, by long-term stability and uniform consistency during measurement operations.

The additives used to formulate these suspensions according to the invention generally have the following particle sizes / diameter /: at least about 95% by weight having a particle size of less than about 150 microns and at least about 20% by weight with a particle size of less than about 30 microns, preferably about 95% by weight. a particle size of less than 150 microns and at least about 20% by weight of a particle size of less than 20 microns, more preferably at least about 95% by weight with a particle size of less than 100 microns and at least about 35% by weight. particle size less than about 10 microns.

The suspension stability is increased when the average particle size is less than about 20 microns, preferably less than about 10 microns.

However, those skilled in the art should know that they are specific. the weight or density of particles of each stabilizer particle will vary according to its composition. For example, the specific gravity of the metal oxide is about 5700 kg / m 2, while the specific gravity of the IRGANOX 1010 is 1150 g / m -1. Thus, the weight fractions of the stabilizers in the slurry as mentioned herein may differ considerably from the volume fractions. At equal weight ratios, the denser stabilizers will have lower solids volumes in the suspensions and thus may give suspensions with lower viscosities, while other factors will be the same.

However, for liquid phases having a specific gravity of about 1, higher density stabilizers will sediment more easily from the suspension than stabilizers whose densities approximate the near-density phase, thereby. the stability, suspension.

These factors should be taken into account when selecting compositions from which stable suspensions of the invention are prepared.

The particle size in microns as reported herein was determined using a MICROTRAC particle size analyzer

Particularly desirable for the purposes of the present invention are additives having the particle size described, which, in fact, are mixtures of particles, i.e. have a bimodal dimensional distribution. When changing the real amounts of larger and smaller particle size distributions in the respective suspension, it allows some control of the suspension viscosity, with lower viscosity suspensions having a larger proportion of larger sized particles in the respective suspension.

It is known that the viscosity of the suspension can drastically increase when the concentration of the suspended solid increases. Generally, at high particle concentrations, the finer the particles, the higher the viscosity of the slurry, it is also known that the maximum volume fraction of particulate solid can be filled into the dispersion, while maintaining the liquidity of the dispersion, there is a "maximum filling" that is a function of the particle shape and dimension distribution.

When the concentration of particles increases and finally the particles touch one another, it is the point at which no other particles can be received in the invariant volume. The minimum volume, per unit of particle size, is a tightly-filled volume. the remainder of this fraction is occupied by an empty © or liquid volume. For example, when the round monodisperse particles reach 74% (v / v) of the particles, they are tightly embedded and no other particles can be added unless the smaller particles are incorporated to fit into interstitial volume between the larger ones. This advantage of engaging with smaller particles can be realized even when the volume concentration of the particles is less than the tight filling as far as the void can incorporate larger particles without causing interference. 26 -

Another property that should be taken into account with regard to suspensions / dispersions is stability to sedimentation. Large particle dispersions are usually not gravimetrically stable. Small particles which have a high surface area increase the formation of the structure in a suitable liquid environment and thus increase the stability of the dispersion. Mixing the distributing particles with the optimum size ratio on the other hand decreases the dispersion viscosity. The larger particles in the mixture can then be stabilized by settling the fine particle networks. The optimal distribution of particles, the presence of fine particles and the proper selection of liquid media are always important.

Unexpectedly, it has now been found that the use of a mixture of sets of particles having different average particle sizes, so the ratio of the average particle diameter in the larger particle size to the average particle diameter of the particle. the smaller particle size is at least 2, preferably 2 to about 100, and the larger particle size of the larger particle size is from about 30% to about 90% by weight of all particles, the resulting suspensions are not only concentrated and markedly lower viscosity compared to a slurry having only fine particles but somewhat stable even when large particles are present. Preference is given to bimodal particle size distributions wherein larger size distributions have a weight average particle size of at least 5 times the weight average particle size distribution of the smaller ones. dimensions.

The suspensions of the present invention are prepared by simply mixing the solid phase with the liquid phase using a high shear mixer such as COWI2SK mix / -2-. - / 27 -

It is to be understood that mixtures of solids and / or mixtures of liquids can be used in the formulation of suspensions.

The concentration of dispersions, i.e. the amount of solids in the liquid phase, is usually of the order of about 0.1 to about 80% by weight, usually about 1 to 60% by weight, preferably about 10 to 70% by weight, more preferably about 10 to 50% by weight, and even more preferably about 30% by weight. up to 60% by weight. The higher the concentration, the less liquid is introduced into the resin mixture. While there is no desire to build any special theory, it is believed that stable suspensions of this invention are affected by the occurrence of controlled agglomeration. In the case of a solids suspension above a certain concentration, usually above about 20% by weight, it is believed that the controlled agglomeration results in a structure that extends through the entire liquid volume and supports the individual particles, thereby preventing particle settling. Particles of different properties, such as polarity, interact in a different degree. Selected liquids of preferred polarity can vary the degree of interactions between particles. Consequently, there is no need to introduce external components into suspensions such as dispersants, surfactants and the like, the sole purpose of which is to ensure particle dispersibility and suspension stability. The present invention provides stable slurries of advantageous viscosity for subsequent mixing with thermoplastic resins. wherein all suspending components are used in the resin. _

- 28 -

Suspensions containing the desired additive in the supernatant form are added directly to the synthetic resin, which can be either solid particles (in pellets, granules, powder, etc.) or in the molten state. they may be premixed with the polymer particles prior to polymer processing operations such as melt extrusion, injection molding and the like, or the slurry may be added directly to the molten polymer during processing The mixing of the slurry and thermoplastic resin may be by spraying or mixing or inverting the resin and slurry in a tape mixer using a two-roller mill, an extruder comprising one screw and multiple screw extruders, a Banbury or Brabender mixer. Suitable processes and apparatus are readily apparent to the skilled artisan in the processing of polymers. from-

Suspension and resin concentrates or premixes can be made and mixed with the virgin resin on the mill before final processing. The rollers on the twin-roll mill can operate at different speeds and temperatures. Despite the simplicity of the grinding operation, extrusion is usually preferred in mixing the slurry and resin, since the extruder can operate continuously, for example, to produce slices that can be cut through a rotating die to form pellets.

The stable suspension can be added to the synthetic resin at the end of the resin treatment, directly after polymerization. resin or polycensation, for example, while still being molten or px-plated or pelletized, or into the polymer as slurry in the reaction medium. However, it is also possible and often more convenient to mix the suspension with the synthetic resin subsequently during one of a number of processing stages, for example before or during extrusion.

The use of a liquid suspension not only facilitates the mixing of the dispersion of the additive with the polymer, but also makes it easier to control the amount of additive mixed with the resin polymer. The slurry may be mixed with the polymer by high shear mixing, tumbling, or directly by dispensing through the discharge port. In any case, a homogeneous distribution of the additive in the polymer is achieved without the risk of thermal degradation of the polymer or additive and without agglomeration of the additive. The advantage of a uniformly dispersed solid, for example a stabilizer, is reflected in the aging properties of the final product. When the additives are. correspondingly dispersed there are no localized areas lacking stabilizer that may fail due to polymer degradation long before the material degrades because the stabilizer is gradually depleted during its lifetime.

The amount of suspension added to the therapoplastic resin may vary and depend in part on the concentration of the suspension, the actual thermoplastic resin, and the effect desired. In the case of a suspension-containing stabilizer, sufficient amount is added to stabilize the resin. Typically, it is sufficient to provide about 0.01 to about 2% by weight, preferably about 0.02 to about 1% by weight of solid stabilizer, based on the weight of the resin. Examples In the following examples, which are intended to illustrate the present invention and do not limit its range in any direction, the components of the suspan / dispersion are described in each example and in each example and the procedures used to prepare and test suspensions / dispersions of thermoplastic polymer blends based on these suspensions. EXAMPLE 1 ETHANOX.RTM. 330 MicromethylETHANOX 330 (1,3,5-trimethyl) -2,4-6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene compound as described herein, 50% by weight of the particles have a particle size of less than about 3.9 microns and about 90% by weight have a particle size of less than about 13.8 microns ETHANOX products are marketed by Ethyl Corporation. CAHB0WAXR Liquid poly (oxyethylene) glycol having an average molecular weight of about 400

CARBOVZAX exhausts are marketed by iami Union

Carbide Chemicals and Plastice Company Corp. Example 2 Micronised ETHANOX 330 described in Example 1 of WESTONR 399 TRIS (nonylphenyl V ° Sulfite Products WESTON axis stabilizers marketed by General Electric Company. Example 3 IRGANOX® 1010 (tetrakis methylene-3 (3 ', 5 ' -di-tert. butyl 4'-hydroxyphenyl) propane, ie methane micronised IRGANOX 1010 defined compound, with 50% by weight of particle size less than 3.2 microns and about 99% by weight having particle size less than about 14.2 microns -Meter IRGANOX products are the antioxidants reported by the naphtha CIBA-C-eigy Corporation, market WESTON 399 described in Example 2. - 33 - Example 4 micronized IRGANOX 1ΟΊΟ non-micronized IRGANOX 1010 as described in Example 3 described in Example 3 except that about 50% by weight particles have a particle size of less than about 53.6 microns and about 90% by weight have a particle size less than about 109.2 microns WESTON 399 described in Example 2. Example 5 mi milled .ETHANOX 330 UCONR LB285 described in Example 1, liquid linear polymer propylene oxide, which my general formula

-CH-O CH. UCON LB285 is a butanol-initiated product having a viscosity of 285 at 37.8 ° C, expressed as Saybolt Uni-versal seconds. The use of this product is particularly advantageous as stable high concentration dispersions can be produced, compared to other liquid carriers of comparable viscosity UCON products are marketed by Union Carbide Chemicals and Plastics Company Inc. Example 6 was micronized as described in Example 1 of ETHANOX 330

R HITEC 180 Hydrogenated Polymer Decene-1 and Octene-1 HITEC products are marketed by the Ethyl Chemicals Group of Ethyl Corporation. EXAMPLE 7 Micronized ETHHANOX 330 NIAXR LG56 described in Example 1 glycerol initiated poly (oxy-propyl) triol of hydroxyl number 56 The products are hydroxypolyoxyalkylenes marketed by Union Carbide Chemicals and Plastics Company Tne. -.- in οζΆ '·

Comparative Example 1 - 35 micromethylETHANOX 330 the non-micromethyl ethanan 330 described in Example 1 described in Example 1 except that about. 50% by weight of particles having a particle size of less than 75.5 microns and 90% by weight have a particle size of less than about 138.7 microns glycerol

The relative oxidative stability of the oxidant-containing resin was determined at ISO ° C at 50 ml per minute of oxygen as determined by the Mean Oxidation Induction Time (OIT) test reported in minutes and described in Chapter 9 of the following publication: H.E.Baix-

Thermal analysis of additives in the polymer

Thermal characterization of E.A. Tuři Ed.

Academy Press, 1981

New York

The stability of each dispersion (slurry) was determined by shooting for a period of time and under certain induced forces, while the gravity of gravity was designated G and visual inspection of these dispersions. The stability in control example 1 was determined by measuring the height of the liquid after centrifuging the cross-sectional area of the cylindrical vessel, thereby converting the height to volume measurements. - '36': '. ud.il <>> · '/ ···· i

R

The viscosity values were determined using a BOHLIN VORi'heometer at 25 ° C at the indicated shear rate.

The yellowness index was determined according to ASTM test D-1925-70. changes in yellowness of the test polymer. A lower numeric value indicates "less yellowness". Example 1 80 g of micronised ETHANOX 330 and 120 g of CARBOWAX 400 were mixed for 5 minutes in a COWLESK mixer operating at 1500 rpm.

Viscosity

Sfability The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability. 7.86 Pa.s at a shear rate of 92.3 reciprocal seconds dispersion was still stable after 4 hours of blasting at 1400 g. Example 2 50 g of micronised ETHANOX 330 and 1 stirred for 5 minutes in a COWLES mixer 1500 rpm. WESTON 399 was the one that worked - 37 - The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability.

The viscosity of 30 Pa.s at a shear rate of 92.3 reciprocal seconds, the stability of the dispersion was still stable after 4 hours of 1400G force blasting. Example 3 50 g of micronised IRGANOX 1010 and 100 g of WESTGN 399 were mixed for 5 minutes in a COWLES mixer operating at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer for viscosity and stability.

The viscosity of 38 Pa.s at a shear rate of 92.3 reciprocal seconds, the stability of the dispersion was still stable after 4 hours of blasting with a force of 1400G. Example 4 25 g of micronised IRGANOX 1010, 25 g of non-micronized IRGANOX 1010 and 100 g of WESTON 399 were mixed for 5 minutes in a COWLES mixer operating at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability.

- 38

The viscosity stability of 32 Pa.s at a shear rate of 92.3 reciprocal seconds of dispersion was still stable after 4 hours of 14OCG blasting.

The mass fraction of particles of the larger particle size was 50% and the average particle size of the larger particle size to the average particle size of the smaller particle size was 14.7.

Comparison with Example 3 shows that the use of the mixed particles as in Example 4 gives a lower viscosity dispersion. Example 5 80 g of micronised ETHANOX 330 and 80 g of UCON LB285 were mixed. 5 minutes in a COWLES mixer that worked at 1500 rpm. The resulting dispersion was then removed from the mixer and tested for viscosity and stability.

The viscosity of 4.2 Pa.s at a shear rate of 92.3 reciprocal seconds, 6.2 Pa, at a shear rate of 5.83 second seconds, the dispersion stability was still stable after 4 hours of 1400 g centrifugation. '^ ί ·' · Wx '> ·' ·: 'V' --- 'z. <',. - λ ^. 'Λν:' - 39 - ¥ The data from this example show that a stable suspension of relatively low viscosity and high concentration is obtained with CUCON LB285. Example 6 50 g of micronised ETHANOX 330 and 150 g of HITEC 180 were mixed for 5 minutes in a COWLES mixer operating at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer and tested for stability.

The stability of the dispersion was still stable after 4 hours of 1400G blasting. EXAMPLE 7 70 g of micronised ETHANOX 330 and 210 g of NIAXuLG-56 were blended for 5 minutes in a COWLES mixer operating at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer and tested for stability.

The stability of the dispersion was still stable after 4 hours of 1400G blasting. 40 -

Comparative Example 1 25 g of micronised ETHANOX 330, 25 g of micromelteltETHANOX 330 and 150 g of glycerol were mixed for 5 minutes in a COWLES mixer that operated at 1500 rpm. . The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability.

A viscosity of 5.5 Pa.s at a shear rate of 92.3 reciprocal seconds, 13 Pa.s at shear rate of 5.83 reciprocal seconds, sample A stability / aliquot / after 1 hour of 1400G force blasting, about 10% volume glycerol was separated. This sample was then centrifuged for a further 3 hours with 1400G. About 40% by volume of glycerol was separated; sample B (aliquot) after 4 hours of silo700G centrifugation separated about 15% by volume glycerol.

A dispersion identical to that of Comparative Example 1 was prepared except that the liquid carrier, glycerol, was replaced by Silicone A as described in detail in Example 28 of this disclosure.

The dispersion of Example 28, which the present invention had, had a significantly lower viscosity and tillage presented by significantly increased stability compared to the dispersion of Example 1.

Compositions as described in Table I were mixed in a HENSCHEL mixer and formed into strips of 0.5 µm thickness extruded at 200 ° C with a slit die attached to the BRABENDER extruder, followed by roller compaction. The resulting tapes / strips were then tested as shown in Table I.

Table I

Composition in grams Ex. Q5Í Ex. Check 2 Check. 3 Kontr. 4 ethylene / / 1-bulen copolymer with melt index 1 1365 1365 1365 1365 1365 micronised ETHANOX 330 described in example 1 0.41 0.41 0.41 ** CARBOWAX 400 0.59 0.6 - UCON LB285 - 0 , 41 - - - - - ™ - - - - Yellowness Index -1,655 -4,505 -0,375 -3,860 -3,520 OIT 43,2 32,8 0 0 x - ETHANOX 330 and CARBOWAX 400 have been added as a one gram dispersion; The example is described in Example 1 xx - .ETHANOX 330 and UCON LB285 were added as 0.82 g of the resin prepared as described in Example 5. awswiassssi. λ, ... - 42 -

The properties shown in Table I clearly show the claimed mixtures as illustrated by the mixture in Example 8 having better oxidative stability compared to controls 2 to 4; and Example 9 has a lower yellowness index compared to controls ee 2-4.

Compositions summarized in Table 2 were prepared, formed into strips, and tested to determine the average oxidation induction time as described with respect to the compositions of Table I,

Table II

Composition Example Check Counter, Counter. in grams 1 0K 5 6 7 Fusion index ethylene / butene-1 1 1365 1365 1365 1365

micronised IRGANOX 1010, described in Example 3 0.41 0.41 WESTON 399 / written in Annex 2 / 0.82 - 0.82 1 27.4 d. IRGANOX and VffiSTON were added as 1.23 g dispersion prepared as described in Example 3 · 43 - The claimed mixtures of Example 10 have improved oxidation stability compared to oxidation stability controls 5 to 7.

Silicone fluids or liquids have been used to reflow dry matter and / or polymer blends in Examples 11-23.

Silicone A is an organomodified polydimethylsiloxane liquid having a molecular weight of about 8000 and a viscosity of about 1.2 Pa.s. Silicone A is a process aid marketed by UCAESIL® PA-1 by Union Carbide

Chemicals and Plastics Company Ino. The melt index and the melt flow ratio represent the melt viscosity of the polyolefin at the specified temperature at different pressures according to

ASTM D-1238. Data were collected using Tinius-R

Olsen Plastograph, Example 1 1 70 g of micronised ETHANOX 330/90% by weight of particles smaller than 19 microns and 50% by weight less than 8.2 microns / and 210 g of Silicon A were mixed with the COWLES mixer at 1500 rpm for 5 minutes. It was found that the resulting suspension had a density of about 1 g / m 2 and a viscosity of about 4 Pa.s at a shear rate of 92 reciprocal seconds at 25 ° C. The suspension was stable enough to withstand 4 hours of 1400G blasting,

It was found to be about 244 ° C, to ETHANOX 330. Although the melting temperature of ETHANOX 330, normal

as a function of the Silicon A ratio by a weight ratio of 3: 1 in this example - 44 - the melt temperature was about 192 ° C. Example 12. 70 g of ZnO / KODOX, 911 / of average size under 1 micron and 21 g of Silicon Silicon® A were mixed in a COWLES mixer at 1500 rpm for 5 minutes. The resulting suspension was found to be sufficiently stable to withstand blasting force of 1400G for 4 hours. Example 13 70 g of micronised ETHANOX 330 from Example 11 and 210 g of hydroxypropyl silicone fluid of formula (CH 3) 3 SiO - [(CH 3) 2 SiO 10 10 - [CH 3 (C 3 H 6 OH ') S 1] w - SifCH 2 -P were mixed in a COWLES mixer at 1500 rpm for 5 minutes. The resulting suspension remained stable after centrifugation for 4 hours at 1400G. Example 14 60 g of KEHEIS L-55R, which is a magnesium carbonate hydroxycarbonate having a particle size distribution such that 90% by weight of the particles were less than 6.2 microns and 180 g of Silicone A was mixed in a COWLES mixer at 1500 rpm for 5 minutes . The resulting suspension was sufficiently stable to withstand 4 hours by blasting the 1400G. Example 15 40 g of micronised ETHANOX 330 from Example 11 was mixed with 120 g of silicone fluid having hindered amine groups of the formula wherein D x is a group. Me - 45 - - SiO -

Stirring was performed on a COSLSS mixer at 1500 rpm for 5 minutes. The resulting suspension was sufficiently stable to withstand 14 hours of 1400G centrifugation. Example 16 40 g of micronised ETHANOX 330 and Example 11 were mixed with 120 g of a silicone fluid having glycidoxypropyl-new moieties of formula MD ^ qDiqM, where Dx is a group

Me

I - SiO -

(ch2K

I o

CHO

GH

Mixing was performed in a COWLES mixer at 1500 rpm for 5 minutes. The resulting suspension was sufficiently stable to withstand 4 hours of 1400G blasting. EXAMPLE 1 40 g of micronised ETHANOX 330 from Example 11 were mixed with 120 g of a silicone fluid having polyethylene oxide groups of the formula MB ^ qqD75 "

Me

SiO

CH 2 CH 2 CH 2 O (CH 2 CH 2 O> hH and n is 6.6 produced by the reaction of allylpolyethylene glycol with an average molecular weight of 350 with hydrosiloxane. Mixing was performed in a COWLES mixer at 1500 rpm for 5 minutes; the resulting suspension was stable enough to hold 4 hours of blasting) For example, 10 g of micronized IRGANOX 1010 having almost all particles of less than about 14 microns, 20 g of ZnO / Kadox 911 (described in Example 12), 20 g of micronized IRGAFOS 168 having substantially all particles less than 1 micron and 150 g Silicone A was stirred in a CGWLES mixer at 1,500 rpm for 5 minutes. The resulting suspension was found to be stable enough to withstand 1400G blast for 4 h. Example 19 10 g of micronised ETHANOX 330 from example 11, 20 gZnO / Kadox 911 (described in Example 12, 20 g micronized IRGAFOS 168 having almost all of the particles of men) s than 1 micrometer and 1 50 g Silicone A was stirred in ether COWLES Mix at 1500 rpm for mingtu for 5 minutes. The resulting suspension was stable enough to withstand 1400G blasting for 4 hours. Example 20 10 g of micronised IRGANOX 1076 having almost all particles less than about 10 microns, 20 g of Reheis L-55R, which is the magnesium aluminum magnesium carbonate described in Example 14, 20 g of micronised IRGAFOS 168 having substantially all particles less than 10 µm. micrometer and 150 g of Silicone Aby was mixed in a COWLES mixer at 1500 rpm for 5 minutes. The resulting suspension was stable enough to withstand 1400G centrifugation for 4 hours. Example 21

This example illustrates how the different methods of dispersing ETHANOX 330 described in Example 11 with a polypropylene homopolymer (HIMONT PROFAX 6801) with a melt index of 0.4 affects the ability of ETHANOX 330 to stabilize polypropylene 48 - against degradation of properties during multiphase extrusion. Example Sample No. 1 contained HIMONT PROFAX6801 powder alone and served as a control. Sample 2 was prepared by dry blending polypropylene powder (HIMONTPROFAX 6801) and ETHANOX 330. Sample 3 was prepared by mixing ETHANOX 330 acetone solution with polypropylene powder (HIMONT PROFAX 6801) and then removing the acetone solvent under reduced pressure. Sample 4 was prepared according to the present invention by suspending ETHANOX 330 in the Silicone Example 11 and mixing the suspension with a polypropylene powder. Sufficient amounts of ETHANOX330 in formulas 2-4 were added to achieve 1000 ppm of ETHANOX330 in the extruded resin.

The resin samples were extruded every 3 times using a 1.9 cm Brabender single screw extruder operating at 260 ° C. The sample was left after each extrusion to determine the melt index and yellowness index. The results are shown in Tables III and IV below, demonstrating that the resin / antioxidant dispersion produced by the suspension of the present invention shows a better color fastness and melt index than those prepared by dry mixing or dissolving the additive in the solvent. solvent by evaporation. Table III Melt Index Sample 1 After. after 2nd after 3rd number value. passage passage passage 1 0.16 1, 84> 5> 5 2 0.22 0.39 0.72 0.9 3 0.15 0.56 0.93 0.97 4 0.20 0.28 0.42 0.60

Table IV

Yellowness Index Sample number Initial value after 1st pass after 2nd pass after 3rd pass 1 0.06 3.71 7.31 X 2 0.96 7.79 10.25 13.05 3 1.53 6.04 9 , 44 13,11 4 -2,76 0,03 2,72 9,80 x The sample showed a poor degradation to be tested. Example 22

This example illustrates how different methods of dispersing a mixture of additives, that is, calcium stearate, IRGAFOSU168 and micronised ETHANOX 330 of Example 11, each at 800 ppm in resin, into the polypropylene homopolymer (HIMONT PROFAX 6801), affect the degradation of the poly-properties. during extrusion.

Sample 1 was prepared by dry blending powders of these three additives with polypropylene powder. Sample 2 was prepared again by dry mixing the powders of the three additives with the propylene powder. Sample 2 was different from Sample 1 using a non-micronized portion of ETHANOX 330 described in Control 1. Sample 3 was prepared by stirring a polypropylene powder with a solution of the three additives in methylene chloride and then removing the solvent under reduced pressure. Sample 4 was prepared according to the present invention by suspending the micronized ETHANOX 330 in Silicon® A using a COWLES mixer.

The suspension was then added with the other two dopolypropylene powder additives and mixed well. Four samples were extruded first on a Werner and Pfleiderer 30 mm twin screw extruder operating at 275 ° C and then twice on a Brabenz extruder used in Example 21. The plates were prepared by melt compression and the yellowness index of each plate was measured. The results are shown in Table V below.

As above, the best results were obtained with the improved dispersion process of the present invention (Sample 4). > ·· .; - 51 -

Table V

Yellowness Index sample number initial value after 3 «pass 1 1.6 11.5 2 -0.3 10.5 3 0.04 9.9 4 -1, 37 S, 5 Example 23

Using the same composition as in Example 22, the following 4 samples were prepared: Sample 1 and 2 were prepared by mixing polypropylene powder with calcium stearate powder, powdered IRGAFOS 168 and an ETHA-NOX 330 suspension in Silicone A. samples 1 and 2 were 5 and 10 microns.

Sample 3, which was not a suspension, was prepared by mixing polypropylene powder with these three additives and the same amount of Silicone A as used in Preparations 1 and 2. The average particle size of ETHANOX 330 in Sample 3 was 10 microns. Finally, the sample was prepared 4 simply by blending the polypropylene powder with the three solid additives. The same procedure as in Example 22 was used, the samples were extruded and plates were prepared to determine the yellowness index. F The results are summarized in Table VI.

Table VII Yellowness Index sample number 1 2 3 4 pe-third pass 10.8 11.5 13.7 13.8 - 52 - Example 24

Again, using the same additives and resin as in Example 22, 3 samples were prepared: Sample 1 was prepared by dry mixing the three-additive polypropylene powder. Sample 2 was prepared by pre-suspending ETHANOX 330 in Silicone A prior to mixing with the propylene powder. Sample 3 was prepared by pre-suspending ETHANOX 330 in a silicone fluid having a hydroxy-propylene ion group

Using the same procedures as in Example 22, specimens were squeezed out and plates were prepared to determine index hardness. The results are shown in Table VII,

Table VIII Yellowness sample Sample number after 3rd pass ý .; value 1 2.03 13.8 2 0.74 11.5 3 0.634 11.7 Example 25 50 g micronised ETHANOX 330 described in Example 1

150 g of Silicone A was mixed for 5 minutes in a COWLES mixer that operated at 1500 rpm. The resulting dispersion of the pack was tested for viscosity a

Viscosity

Stability - 53 - was taken from a COWLES mixerustable, 4.95 Pa.s at a shear rate of 5.83 reciprocal seconds, 4.35 Pa.s at a shear rate of 92.7 reciprocal seconds of dispersion was still stable at 4 hours by 1400G blasting. Example 26 50 g of micronised ETHANOX 330 described in Example 1a 50 g of Silicone A were mixed for 5 minutes in a COWLES microneer operating at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer for viscosity and stability.

Viscosity 62.69 Pa.s at shear rate 5.83 reciprocal seconds, and 30.35 Pa.s at shear rate 92.7 reciprocal seconds

The stability of the dispersion was still stable after 4 hours of 1400 0 blasting. Example 27 50 g of non-micronized ETHANOX 330 described in control 1

and 150 g of Silicone A was mixed for 5 minutes in a COWLES mixer that operated at 1500 rpm. The resulting dispersion was then removed from the COWLES microscope and tested for viscosity and stability.

Viscosity 4.7 Pa. s pri. 5.83 reciprocal seconds shear rate

The stability of the dispersion was still stable after 1 hour of 100G blasting, about 60% of the dispersion was deposited at 70CG for 4 hours, about 60% of the dispersion settled after 1 hour of 1400G blasting. Example 28 25 g of micronised STHANOX 330 described in Example 1.25 g of non-micronized ETHANOX 330 described in Example 1 and 150 g of Silicone A were mixed for 5 minutes in a COWLES mixer which operated at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability

The viscosity of 4.6 Pa.s at a shear rate of 5.83 reciprocal seconds, 3.9 Pa.s at a shear rate of 92.7 reciprocal seconds, the stability of the dispersion was still stable after 4 hours of 1400 g silencing. '• / IV': '7-P ·:' '55 -' '<

The mass fraction of particles of the larger particle size was% o. The proportion of the average particle diameter in the larger particle size to the average particle diameter of the smaller particle size was 12.9.

Comparison with Example 27 shows the advantage of mixed particle sizes with respect to dispersion stability, as shown by this example.

Comparison with Example 25 shows the advantage of mixed particle sizes with respect to dispersion viscosity, as shown by this example. EXAMPLE 29 25 g of ETHANOX 330 described in Example 1, 25 g of non-micronised ETHANOX 330 described in Comparative Example 1a of 50 g of Silicone A were mixed for 5 minutes in a COWLES migraine which operated at 1500 rpm. The resulting dispersion was then removed from the COWLES mixer and tested for viscosity and stability.

The viscosity of 25.67 Pa.s at a shear rate of 5.83 reciprocal seconds of 18.32 Pa.s at a shear rate of 92.7 reciprocal seconds, the dispersion was still stable after 4 hours of 1400G blasting.

Iir-Stability / - 56 -

Comparison with Example 26 shows the advantage of mixed particle sizes with respect to viscosity as shown by this example.

Claims (68)

PATENT CLAIMS A stable suspension comprising a solid phase and a liquid phase, characterized in that the solid phase consists essentially of a mixture of two sets of particles having different average particle sizes such that the ratio of the average particle diameter in the larger particle size to the average particle diameter in the smaller particle size set is at least about 2, and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles and at least about 95% by weight thereof has a particle size of less than about 150 microns and at least about 20% of these particles have a particle size of less than 30 microns. 2. A stable suspension according to claim 1 wherein said ratio is from about 2 to about 100 and the weight of the larger particle size is from about 30% to about 90% by weight of all said particles. 3. A solid and liquid phase stable suspension characterized in that the solid phase consists essentially of two sets of particles having a different average particle size such that the ratio of the average particle diameter in the larger particle size to the average particle size in the smaller particle size the particle size is at least about 2, and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles and at least about 95% by weight of the particles are 4. The stable suspension of claim 3 wherein said ratio is from about 2 to about 100 and the weight of the larger particle size is from about 30% to about 90% by weight of all of said particles. 5. A stable dispersion, characterized in that it comprises particles of a stabilizer for thermoplastic resins as a solid phase, and as liquid phase of this dispersion it comprises liquid silicone, a liquid stabilizer for thermoplastic resins, liquid hydroxylated polyoxyalkylene or alcoxy terminally blocked products of this polyoxyalkylene, liquid poles (alpha- olefin) or a hydrogenated product of this poly (alpha-olefin), or mixtures thereof. ; <; 5: i ···· '' w;,; _ ">" I "->? ' particles of less than about 100 microns and at least about 35% of these particles have a particle size of less than about 10 microns; 6. The stable suspension of claim 5 wherein at least about 95% by weight of the particles have a particle size of less than about 1.50 microns and at least about 20% by weight have a particle size of less than about 30 microns. 7. A stable suspension according to claim 5 wherein at least 95% by weight of said particles have a particle size of less than about 100 microns and at least about 35% by weight of said particles have a particle size of less than about 10 microns. ? 59: ΛΪν, /ù λ '' 1 Ά? Λiiil '7 - 59 - which have a different average particle size, so that the average particle diameter in the larger particle size to the average particle diameter of the smaller particle size is at least 2 and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles and at least 95% by weight of these particles have a particle size of less than about 150 microns and at least about 20% of these particles have particle size less than about 30 microns. 8. The stable suspension according to item 5, the solid phase consists essentially of a mixture characterized by one set of particles 9. A stable suspension according to claim 8 wherein said ratio is from about 2 to about 100 and the weight of said larger particle size particles is from about 30% to about 90% by weight of said particles. 10. A stable suspension characterized in that it contains the thermoplastic resin stabilizer particles as a solid phase and contains a liquid stabilizer for thermoplastic polymers as the liquid phase of the present invention. 11. The stable suspension according to claim 10, wherein at least 95% by weight of said particles have a particle size of less than about 150 microns and at least about 20% by weight of said particles have a particle size of less than about 30 microns. 12. The stable suspension of claim 10 wherein at least about 95% by weight of the particles have a particle size of less than about 100 microns and at least about 35% by weight of these particles have a particle size of less than about 10 microns. «M8S® - 60 - 13. A stable suspension according to claim 10, wherein the solid phase consists essentially of a mixture of two sets of particles having different average particle sizes such that the average diameter of the particles in the set of larger particle sizes to the average particle diameter in the set is smaller in size. the particle size is at least 2 and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles, and at least about 95% by weight of these particles have a particle size of less than about 150 microns and at least about 20% of these particles having a particle size of less than about 30 microns. 14. The stable suspension of claim 13 wherein the ratio is from about 2 to about 100 and the weight of the larger particle size particles is from about 30% to about 90% by weight of all said particles. 15. A stable suspension according to item 10, characterized in that the phase consists essentially of a mixture of two sets of particles having a different average particle size such that the average particle diameter in the larger particle size to the average particle size in the sample is the smaller particle size is at least about 2, and the particle weight of the larger particle size is from about 30% to about 90% by weight of all particles and at least about 95% by weight of these particles have a particle size of less than about 100 microns and at least about 35% than about 10 microns. these particles have smaller particle sizes 16. The stable suspension of claim 15, wherein said ratio is from about 2 to about 100 and the weight of the particles is from about 60% to about 90% by weight of said larger particle size. 17. A stable suspension according to claim 10 wherein the liquid stabilizer is phosphite. 18. The suspension according to claim 17, wherein the phosphite is tris (nonylphenyl) phosphite. 19. A suspension according to claim 10, comprising particles of (1,3,5-trimethyl) -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene. 20. A stable suspension according to claim 10, characterized in that it comprises particles (tetrakis [methylene-3- (3 ’, 5'-di-tert-butyl-4'-hydroxyphenyl) propionate]. 21. A stable suspension according to claim 10, comprising (1,3,5-trimethyl) -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene a. liquid phase tris (nonylphenyl) phosphite. 22. A stable dispersion according to claim 10, characterized in that it comprises particles of tetrakismethylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate methane and tris (nonylphenyl) phosphite as the liquid phase. 23. A stable suspension comprising particles of a stabilizer for thermoplastic polymers as a solid phase and a liquid phase of the suspension of liquid hydroxylated polyoxyalkylene or alkoxy-blocked products of the polyoxyalkylene. - 62 - 24. A stable suspension, characterized in that it comprises particles of a stabilizer for thermoplastic polymers as a solid phase and liquid hydroxylated polyoxyalkylene or alkoxy terminal products thereof as a liquid phase, wherein at least about 95% by weight of these particles have a particle size less than 150 micrometers and at least about 20 wt.% Of these particles have a particle size of less than about 30 microns. 25. The stable suspension of claim 24 wherein at least about 95% by weight of said particles have a particle size of less than about 100 microns and at least about 35% by weight of said particles have a particle size of less than about 10 microns. 26. A stable suspension according to claim 24, wherein the solid phase consists essentially of a mixture of two sets of particles having a different average particle size such that the ratio of the average particle diameter in the larger particle size to the average particle diameter in the particle set. the smaller particle size is at least 2, and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles, and at least about 95% by weight of these particles have a particle size of less than 150 microns and at least about 20% of the particle size less than about 30 microns. 27. A stable suspension according to claim 26 wherein the ratio is from about 2 to about 100 and the weight of the larger particle size is from about 30% to 90% by weight of all said particles. - 63 - 28. A stable suspension according to claim 24, wherein the solid phase w consists essentially of a mixture of two sets of particles having a different average particle size such that the ratio of the average particle diameter in the larger particle size to the average particle diameter in the core. the smaller particle size is at least about 2 and the particle size of the larger particle size is 30% to about 90% by weight of all particles and at least 95% by weight of these particles have a particle size of less than about 100 microns and at least about 35% of these particles having a particle size of less than about 10 microns. 29. The stable suspension of claim 28 wherein said ratio is from about 2 to about 100 and the weight of said larger particle size is from about 30% to about 50% by weight of all particles. 30. A stable suspension according to claim 24 wherein the hydroxylated polyoxyalkylene has the formula HO - (- CH2 --CH2O9 --H. 31. A stable suspension according to claim 24 wherein the hydroxylated polyoxyalkylene comprises ethylene oxide and propylene oxide units. 32. A stable suspension according to claim 24, wherein the hydroxylated polyoxyalkylene has the formula s, - n, and vWV. - 64 - K Ί CK-J nu nu ...... π (n - v / n p in n - in "b - - c where R 1 is hydrogen or alkyl of 1 to 6 carbon atoms inclusive, 33. A stable suspension according to claim 24, wherein the hydroxylated polyoxyalkylene is a butanol initiated propylene oxide polymer of formula R @ 4 --CH2 --CH2 --O - CH--. 34. A suspension according to claim 24, comprising (Ί, 3,5-trimethyl) -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene particles. 35. A suspension according to claim 24 which comprises particulate methetrakismethylene-3- (35'-di-tert-butyl-4'-hydroxyphenyl) propionate. 36. A stable suspension according to claim 24, comprising particles of (2 1,3,5-trimethyl-2, 4, 6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and poly (oxyethylene) glycol as a liquid phase 37. A suspension according to claim 24 comprising (1,3,5-trimethyl) -2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and hydroxy polyoxypropylene as a liquid phase. 38. A stable suspension, characterized in that it contains particles of stabilizer for thermoplastic polymers as a solid phase and as liquid phase of this liquid-liquid suspension (alpha-olefin) or hydrogenated products thereof. 39. The stable suspension of claim 38 wherein at least about 95% by weight of said particles have a particle size of less than about 150 microns and at least about 20% by weight of said particles have a particle size of less than about 30 microns. 40. The stable suspension of claim 38 wherein at least about 95% by weight of said particles have a particle size of less than about 100 microns and at least about 35% by weight of said particles have a particle size of less than about 10 microns. 41. A stable suspension according to claim 38, wherein the solid phase consists essentially of a mixture of two sets of particles having different average particle sizes such that the ratio of the average diameter of the particles in the larger particle size to the average particle diameter of the smaller particle size is at least about 2 and more particles of larger particle size are from about 30% to about 90% by weight of all particles, and at least about 95% by weight of these particles have particle sizes less than about 150 microns and at least about 20% of these particles have particle sizes less than about 30 microns. - 66 - 42. A stable suspension according to clause 41, wherein the ratio is from about 2 to about 100 and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles. 43. A stable suspension according to claim 38, wherein the solid phase consists essentially of a mixture of two sets of particles having different average particle sizes such that the ratio of the average particle diameter in the larger particle size to the average particle diameter in the array is greater. the smaller particle size is at least about 2 and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles, and at least about 95% by weight of these particles have a particle size of less than about 100 microns and at least about 35% thereof. having a particle size of less than about 10 microns, 44. A stable suspension according to clause 43, wherein said ratio is from about 2 to 100 and the particle size of said larger particle size is from about 30% to about 90% by weight of all said particles, 45. A suspension according to claim 38 comprising particles of (1,3,5-trimethyl) -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene. 46. A stable suspension according to claim 38 wherein the poly (alpha-olefin) is a copolymer of decene-1 and octene-1 or its hydrogenated products. 47. A stable suspension according to claim 38, comprising (1,3,5-trimethyl) -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene particles and liquid phasehydrogenated copolymer of decene-1 and octene-1. - 67 - 48. A stable suspension, characterized in that it contains the thermoplastic resin stabilizer particles as a solid phase and contains silicone as the liquid phase of the suspension. 49. Stable suspension characterized in that it contains stabilizer particles for thermoplastic resin as a solid phase &amp; and the liquid phase of the suspension comprises a polysilorganosiloxane polymer with a suspended suspension-enhancing polar group, wherein at least 95% by weight of the particles have a particle size of less than 150 microns and at least 20% by weight of these particles have a particle size of less than about 30 microns. 50. The stable suspension of claim 49 wherein at least about 95% by weight of the particles have a particle size of less than about 100 microns and at least about 35% by weight of the particles have a particle size of less than about 10 microns. 51. A stable suspension according to claim 49, wherein the solid phase consists essentially of a mixture of two sets of particles having different particle sizes such that the ratio of the average particle diameter of the larger particle size to the average particle diameter of the smaller particle size the particle size is at least about 2, and the particle size of the larger particle size is from about 30% to about 90% by weight of all particles, and at least about 95% by weight of these particles have a particle size of less than about 150 microns and at least about 20% of these particles have a particle size of less than about 30 microns. - 68 - 52. A stable suspension according to claim 51 wherein the ratio is from about 2 to about 100 and the weight of the larger particle size particles is from about 30% to about 90% by weight of all of the particles. 53. A stable suspension according to claim 49 wherein said polar group is a monovalent organic group containing a residue selected from hydroxy, hydroxyalkyl, carboxyl, amino, amide, carbamate, aldehyde, nitrile, phenol, vicinal epoxy, alkoxy, phosphite, phosphine, phosphonate, carboxylic acid ester, polyether, polyalkylene oxide, thiol or sulfide. 54. A stable suspension according to claim 49, wherein the polyorganosiloxane polymer has the formula Rc10R6 -Si-O-R-Si-O-R'-Si-R1-Si-O-R-. Wherein the substituents R to R may be the same or different and are selected from alkyl groups, aryl groups of amonovalent radicals containing radicals selected from the group consisting of hydroxy, hydroxyalkyl, carboxy, amino, amide, carbamate, aldehyde, nitrile, phenol, vicinal epoxy, alkoxy, phosphite, phosphine, phosphonate, carboxylic ester, polyether, polyalkylene oxide, thiol - 69 - and sulfide and where x, y and z may be the same or different x, y and z are between 1 to 3000. 55. A stable dispersion according to claim 54, wherein R 1 to R 6 and R 6 to R 12 are selected from alkyl and aryl groups, R 1 and R 2 are selected from said monovalent organic groups, x is between 0 to 2000, y has a value between 1 and 500 and has a value between 0 and 500. 56. A stable suspension according to claim 48 wherein said resin stabilizer is phosphite, phosphonite, hindered phenol, thiodipropionate, hindered amine, benzophenone, or mixtures thereof. 57 · Stable suspension according to claim 56, characterized in that the organic phosphite is a bis-substituted pentaerythritol diphosphite. 58. A stable suspension according to claim 56 wherein the resin stabilizer is tri-dodecylphosphite, bis- (2,4-di-butylphenyl) pentaerythritol diphosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite. octadecyl-3- (3-5'-di-t-butyl-4-hydroxyphenyl) propionate, dilaurylthiodopropionate, tetrakis (methylene-3 (3 ', 5'-di-tert-butyl-4' - hydroxyphenyl) propionic methane, 1,3,5-triethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2,2 '- ethylidene-bis (4,6- di-tert-butyl) phenol or N, N'-diphenyl-N, N'-di-2-naphthyl-p-phenylenediamine. 59. A stable suspension according to claim 48 wherein the polyorganosiloxane liquid is polydimethylsiloxane having pendant polyether groups and the resin stabilizer is 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert. -butyl-4-hydroxybenzyl) benzene. F 60. The stable suspension according to claim 48, wherein the polyorganosiloxane is a polydimethylsiloxane having hydroxyalkyl groups attached and the resin stabilizer being 1,3,5-trimethyl-2,4,6-tris (3,5-diethyl). tert-butyl 4-hydroxybenzyl) benzene. 61. A composition comprising a stable suspension as defined in (1) and a thermoplastic resin. 62. A composition comprising a stable suspension which is defined at a point and a thermoplastic resin. 63. A composition characterized in that it contains a stable suspension as defined in point 10? and thermoplastic resin. 64. A composition comprising a stable suspension as defined in point 23 and a thermoplastic resin. 65. A composition comprising a stable suspension as defined in claim 38 and a thermoplastic resin. 66. A composition comprising a stable suspension as defined in claim 48 and a thermoplastic resin. 1 71 - 71 - 67. The composition of claim 61 wherein the thermoplastic resin is an olefin polymer. 1 * 68. A composition according to claim 67 wherein the polymer is a copolymer of ethylene and butene. 4